Field of the Invention
The present invention relates to a battery terminal applicable to a lithium ion battery, for example, a method for manufacturing the battery terminal, and a battery including the battery terminal, and more particularly, it relates to a battery terminal including different metal layers, a method for manufacturing the battery terminal, and a battery including the battery terminal.
Description of the Background Art
A battery terminal including different metal layers is known in general, as disclosed in Japanese Patent No. 5202772, for example.
Japanese Patent No. 5202772 discloses a negative-electrode terminal made of a clad material in which an Al layer and a Ni—Cu alloy layer are bonded to each other. The clad material constituting this negative-electrode terminal is a so-called inlay clad material having the Ni—Cu alloy layer embedded in a groove formed in the Al layer. A region of the Al layer other than a region where the Ni—Cu alloy layer of the negative-electrode terminal is embedded is welded to a bus bar made of Al. The Ni—Cu alloy layer of the negative-electrode terminal is welded to a negative-electrode columnar portion made of Cu, exposed through a hole formed in the region where the Ni—Cu alloy layer is embedded. Consequently, the negative-electrode terminal is configured to be capable of easily electrically connecting the bus bar and the negative-electrode columnar portion made of different metal materials to each other.
However, the negative-electrode terminal disclosed in Japanese Patent No. 5202772 is made of the inlay clad material, and hence the Ni—Cu alloy layer must be precisely arranged at a proper position in order to be embedded in the groove of the Al layer. Therefore, the clad material itself is not easily prepared, and it is difficult to improve mass productivity at the time of mass production. Thus, it is desired to improve the mass productivity of the negative-electrode terminal.